A photovoltaic solar module, also referred to as a solar panel, typically comprises a plurality of solar cells which convert radiant energy (as a rule sunlight) into electrical energy. The solar cells are arranged next to one another between a layer on the front side which faces the radiation and a layer on the rear side, and are electrically interconnected within this sandwich structure. The two layers are for example panes of glass. The sandwich structure may further be surrounded by a frame.
On the rear side of a solar module there is usually provided a connection device or connection box, which is used to connect contact elements of the solar module coming from the solar cells, for example connection foils or connection strips which are brought out on the rear side, to lines or cables. A plurality of connection devices and hence solar modules can be connected together via the cables. For example, serial interconnection of solar modules is conventional in order to achieve the generation of higher voltages. Furthermore, solar modules may be connected via the cables to devices such as for example an inverter.
In a conventional configuration, a connection device, which is also referred to as a connection box or solar box, comprises a housing with through openings for passing the contact elements of a solar module through, and a contacting means arranged within the housing for contacting the contact elements. The contacting means comprises for example conductor bars which are connected to clamps, which bars can be connected to the contact elements of the solar module, and to which the above cables or their conductors can also be connected. In this case, the cables may be fastened to the housing in the region of a cable end, for example by a cable gland provided on the housing. At the opposite end of the cable, the cables are usually provided with a plug-and-socket connector, which permits simple connection of cables of different connection devices (for example for serial interconnection) or attachment of cables to an inverter.
One disadvantage of the known connection devices is that the cables which are fastened to the connection devices by one cable end can be held on or fixed to the connection devices only inadequately or not securely. One current practice is for example temporarily to fix the cables to the housings of the connection devices for storage or transport with the aid of cable ties, fastening clips or by using adhesive tape. This is linked to problems such as for example dangling of the cables, and possibly damage thereto during transport. The temporary fixing of the cables furthermore makes it difficult to mount a connection device on a solar module and to carry out a final electrical inspection on a solar module, in which the solar module in question is contacted via the cables of the connection device which is arranged on the solar module.
One further problem is that the plug-and-socket connectors which are arranged on the cable ends are open or freely accessible. This means that contact elements of the plug-and-socket connectors may be exposed to influences such as for example water and dirt, which means that a plug-in connection realised by means of a thus-“contaminated” plug-and-socket connector may be compromised.